1. Field of the Invention
The present invention relates generally to orthopedic braces, particulary to a shoulder brace for providing support to the shoulder area.
2. Description of the Related Art
The ball and socket joint of the human shoulder provides for free movement of the arm. The area of contact between the various bones in the shoulder is minimal and the shoulder joint is dependent upon surrounding muscles, and to a lesser extent ligaments, tendons and fibrocartiledge, for its integrity and functionality. The muscular and bone composition of the shoulder is the subject of extensive medical study and while a more detailed discussion of the anatomy of the shoulder is not necessary for the purposes here, such a discussion can be found in most basic human anatomy books. Because of its construction, the shoulder joint is capable of flexion, extension, adduction, abduction, rotation and circumduction movement. Also because of its construction, the shoulder joint is susceptible to a great number of injuries.
Injuries are commonplace in various activities that require constant motion of the shoulder joint or subject the shoulder to stress. For example, the overhand throwing motion used in baseball is an unnatural motion that can cause shoulder muscle strains or tears, including injury to the deep rotator muscles or rotator cuff of the shoulder and arm. Participants in contact sports such as rugby and football often suffer shoulder injuries, e.g., dislocation of the ball and socket joint as well. Once an injury to the shoulder area has occurred, it is frequently necessary to support the joint area to both facilitate the convalescing process in certain situations, and minimize discomfort due to the injury. Additionally, it is advantageous to provide support to the shoulder area to help prevent shoulder injuries to individuals who are particularly susceptible to such injuries.
Anterior shoulder instability most commonly develops when the restraints of the humeral head are inadequate or excessive force is being applied, usually when the shoulder is in abduction, external rotation, and extension. Anterior shoulder stability is usually maintained by the anteroinferior glenohumeral ligament as well as the subscapularis muscle and the middle glenohumeral ligament. Weakness in these allows excessive anterior translation of the humeral head in the glenoid fossa, the humeral head being the ball and the glenoid fossa being the socket of what is commonly referred to as the ball and socket joint of the shoulder. Since the anteroinferior glenohumeral ligament is especially stressed when the arm is positioned in abduction, extension or external rotation, it is reasonable to assume that preventing or limiting these positions might be beneficial for patients with instability. However, by preventing or limiting those positions, athletes who suffer these types of injuries or weaknesses would be particularly impaired in their ability to perform their respective activity.
There are a number of braces and harnesses known in the art that alleviate pressure on various points of the shoulder joint. For example, U.S. Pat. No. 3,906,944 issued to Christian discloses a shoulder harness that prevents damage to the muscles, tendons and ligaments in the shoulder area and also provides support to prevent the dislocation of the shoulder. The shoulder harness disclosed in the Christian patent, however, severely restricts the movement of the upper arm with respect to the shoulder, thereby restricting the movement of the ball and socket joint. Furthermore, existing braces, such as the Christian harness, are cumbersome and difficult for a wearer to put on, particularly because of the shoulder injury. Most known braces and harnesses also neither allow the wearer to increase or decrease the amount of support around the area of the shoulder, nor are capable of being adjusted to conform to the particular body size of the wearer.
Furthermore, known shoulder braces are generally excessively restrictive on arm movement while they provide inadequate support for preventing anterior dislocation of the shoulder joint.
U.S. Pat. No. 5,188,587 issued to McGuire et al. teaches an active shoulder brace made of a resilient fabric-like material. The shoulder brace taught by McGuire et al. includes a sleeve portion which is designed to fit around the upper end of the upper arm of a patient and it includes straps that are wrapped over and around the sleeve portion and attached to a torso belt which anchors the straps attached to the sleeve portion. When a patient wearing the shoulder strap taught by McGuire et al. raises their arm, the straps tighten and provide support to the shoulder joint.
However, as with the other known shoulder straps, the shoulder strap taught by McGuire et al. exerts a substantial amount of force to the top of the shoulder and the upper arm when the patient wearing the strap raises their arm and far less pressure or support to the anterior, posterior and medial side of the shoulder joint. The result is that the shoulder strap provides a strong force which inhibits upward movement of the arm of the patient yet provides only moderate or little support or pressure to the anterior, posterior and medial sides of the shoulder joint. As discussed above, patients with chronically dislocating shoulders experience problems with the humeral head of the shoulder moving in an anterior direction out of the glenoid fossa and thereby dislocating. Therefore, the shoulder straps of the prior art provide an excessive amount of force that inhibits motion of the arm while ineffectively preventing the anterior dislocation of the shoulder joint. Therefore, it is desirable to provide a shoulder brace which can compensate for weaknesses in tissues such as the glenohumeral ligament, the subscapularis muscle and the middle glenohumeral ligament, without causing excessive restriction to arm movement.